1. Field of the Invention
The present invention relates to a disk apparatus for driving optical disks (for example, CD-R/RW, DVD-R/RW/RAM/+R/+RW, etc.) as recording media for recording a large amount of data in various computer systems.
2. Description of the Related Art
In general, disk apparatuses built in personal computers (hereinafter, referred to as PCs) use disk trays for loading optical disks that move forward and backward. The optical disks loaded into the disk trays are driven in the main bodies of the disk apparatuses to record or reproduce data.
On the other hand, a slot-in type disk apparatus without using the disk tray has been widely used to reduce the thickness and size of the PC. Since the slot-in type disk apparatus does not use a disk tray for loading and unloading an optical disk into the main body thereof, a user inserts a half or more of the optical disk into a slot, and the optical disk is then automatically loaded by the operation of a mechanism into the main body of the apparatus.
Once the optical disk is loaded into the main body of the disk apparatus, it is mounted on a turntable to rotationally drive the optical disk. Usually, in this construction, a clamp head formed integrally with the turntable goes up to a prescribed position and clamps a central hole of the optical disk.
FIG. 18 is a diagram illustrating the operation of the clamp head as it clamps onto the optical disk in a conventional slot-in type disk apparatus. In the configuration shown in FIG. 18, a driven pin 103 provided at the side surface of a frame member 101 is located at a straight part of a cam groove 102a while a slide member 102 is moving until it reaches the state shown in FIG. 18A, and thus the frame member 101 is kept in a down state. However, when the slide member 102 is further moved, the camp groove 102a pushes up the driven pin 103 from the state shown in FIG. 18(A) to the state shown in FIG. 18(B), so that a clamp head 105 attached to a motor shaft of a spindle motor 104 fixed to the frame member 101 is inserted into the central hole of the optical disk D. Then, the spindle motor 104 is raised so that the optical disk D is interposed between a turntable 107 and a convex portion 106a formed in a cover chassis 106. At this time, the clamp head 105 is completely inserted into the central hole of the optical disk D, and a chuck claw 105a of the clamp head 105 holds the optical disk on the turntable 107.
Then, when the cam groove 102a is moved to the state shown in FIG. 18(C), the frame member 101 is separated from the convex portion 106a together with the optical disk D held by the clamp head 105 and goes down a little. At that time, by driving the spindle motor 104 at the above height, the optical disk D is driven so that the recording and reproduction of data on the optical disk D is started (for example, see Patent Document 1).
[Patent Document 1]—Japanese Unexamined Patent Application Publication No. 2002-117604
In the disk apparatus constructed in this way, the upward and downward movement of the clamp head 105 is based on the driven pin 103 that is moved up and down corresponding to the horizontal reciprocation of the slide member 102, and thus the driven pin 103 should be accurately guided into the cam groove 102a. For this reason, the clearance between the driven pin 103 and the cam groove 102a should be kept in a so-called rigid state where a frictional resistance is not generated.
On the other hand, the frame member 101 is provided with the spindle motor 104, the turntable 207, the clamp head 105, and a head unit for applying a laser beam to the optical disk D. An objective lens of the head unit that is composed of a tracking coil and a focus coil for accurately forming a beam spot on the pits of the optical disk is supported in a cantilever state and is servo-controlled. Therefore, external vibrations are most easily applied to the objective lens of the head unit, and sufficient consideration for vibrations must be taken for the objective lens.
Therefore, in the conventional disk apparatus, a buffering structure is provided for axially supporting the frame member 101 using a plurality of elastic members. The buffering structure is also employed in a conventional slot-in type disk apparatus. However, in the buffering structure, only the vibrations generated horizontally are buffered not the vibrations generated vertically.
That is, as described above, the frame member 101 should always be accurately moved up and down, and thus the driven pin 103 and the cam groove 102a are made rigid. From an inverted point of view, unnecessary up-and-down movement is prevented in this construction, and the up-and-down movement of the frame member 101 is actively prevented. In this state, the frame member 101 cannot absorb impacts generated in a vertical direction. Therefore, vertical impacts are directly transferred to the frame member 101, and thus the above construction is not sufficient as a buffering structure.